Certain recipes are only readily available to characters of a specific faction, usually due to them being a reward for a quest specific to that faction, or the vendor for the recipe being in an area only accessible to that faction. Sometimes, these recipes are available from a neutral auction house, assuming that they're not bind on pickup.

As of Patch 3.0.8, the total number of recipes actually in the game currently is 161. If you wish to determine which recipes you are missing, you can use the in-game mod Ackis Recipe List.